---
type: source
title: "Chinese Scientists Publish He-3-Free ADR Alloy (EuCo2Al9) in Nature — Response to DARPA Call"
author: "CAS Institute of Theoretical Physics / Shanghai Jiao Tong University — via Interesting Engineering, SCMP"
url: https://interestingengineering.com/science/worlds-coldest-alloy-could-shrink-quantum-fridges
date: 2026-02-00
domain: space-development
secondary_domains: []
format: article
status: processed
priority: medium
tags: [helium-3, adr, quantum-computing, china, materials-science, substitution-risk, rare-earth]
flagged_for_leo: ["China's rare-earth advantages in He-3-free ADR materials — geopolitical strategic minerals angle"]
processed_by: astra
processed_date: 2026-03-19
enrichments_applied: ["falling launch costs paradoxically both enable and threaten in-space resource utilization by making infrastructure affordable while competing with the end product.md"]
extraction_model: "anthropic/claude-sonnet-4.5"
---

## Content

Chinese Academy of Sciences researchers published a rare-earth alloy (EuCo2Al9, ECA) in Nature in February 2026 — less than two weeks after DARPA's January 27 urgent call for He-3-free cooling.

Technical properties of EuCo2Al9:
- Metallic spin supersolid with high thermal conductivity (unlike most ADR materials)
- Giant magnetocaloric effect enabling efficient sub-kelvin refrigeration via ADR
- Coexisting spin orders and strong quantum fluctuations
- High thermal conductivity allows efficient heat extraction (key ADR challenge)
- Potential for mass production noted by CAS
- Pure metal refrigeration module successfully developed

Cooling mechanism: Adiabatic Demagnetization Refrigeration (ADR) — apply magnetic field to align atomic magnets (releases heat) → isolate system → remove field → magnets unalign (absorbs heat) → temperature drops. Solid-state, no liquid He-3 required.

Strategic context:
- China responded to a US DARPA call within two weeks with a Nature-quality paper
- China has significant rare-earth resource advantages vs. US and Europe
- Reducing He-3 dependence aligns with Chinese strategic interests (avoiding US/Russia tritium supply dependence)
- SCMP headline: "China's new rare earth alloy might revolutionize quantum computing — it may surprise DARPA"

**Critical technical caveat:** ADR systems typically reach 100-500mK. Superconducting qubits require 10-25mK. Whether EuCo2Al9 ADR can reach qubit operating temperatures without He-3 pre-cooling is unconfirmed in search results. This is the decisive technical gap.

## Agent Notes

**Why this matters:** This is the most technically credible He-3-free alternative in the near term, backed by a major Chinese research institution and published in Nature. But the temperature floor question is critical — if ADR with ECA can't reach 10-25mK, it needs He-3 for pre-cooling and is not a full substitute.

**What surprised me:** The Chinese strategic framing in SCMP — China is not just responding to DARPA, it's positioning itself to be the supplier of He-3-free ADR materials using its rare-earth advantages. This could create a new strategic minerals dynamic where China controls ADR material supply chains while the US tries to develop lunar He-3 supply chains. Two competing paths to solving the same supply problem.

**What I expected but didn't find:** Temperature floor specification for EuCo2Al9 ADR — does it reach 10-25mK or only ~100mK? This determines whether it's a direct substitute or a partial substitute needing He-3 pre-cooling.

**KB connections:**
- Pattern 4 (He-3 demand from quantum computing): counter-evidence to "no terrestrial alternative at scale"
- [[China is the only credible peer competitor in space...]] — this adds a rare-earth materials dimension to China's space competitive strategy

**Extraction hints:** Extract two claims: (1) EuCo2Al9 as a credible He-3-free ADR path with high thermal conductivity (the key differentiator from prior ADR materials), with caveat on temperature floor uncertainty. (2) China's strategic use of rare-earth advantages to develop He-3-free alternatives as a geopolitical hedge against US/Russia tritium supply dependence.

**Context:** Kiutra (Germany) is also using ADR for He-3-free cooling and is already commercially deployed. The EuCo2Al9 paper extends this by using a novel alloy with higher thermal conductivity — potentially solving the practical engineering challenges that limit existing ADR systems.

## Curator Notes

PRIMARY CONNECTION: Pattern 4 (He-3 demand) — this is the strongest academic counter-evidence to "no terrestrial alternative at scale."

WHY ARCHIVED: Nature publication quality + Chinese strategic framing + rapid DARPA response = highest-credibility signal that He-3-free ADR is a real research direction with institutional backing.

EXTRACTION HINT: Lead with the temperature floor uncertainty as the key caveat. The alloy is promising but its deployment-readiness for quantum computing (vs. lab demonstration) depends on the temperature question. Extract as experimental confidence claim pending temperature validation.


## Key Facts
- EuCo2Al9 published in Nature in February 2026 by CAS Institute of Theoretical Physics and Shanghai Jiao Tong University
- DARPA issued urgent call for He-3-free cooling on January 27, 2026
- China controls approximately 70% of global rare-earth production and processing
- ADR systems typically reach 100-500mK operating temperatures
- Superconducting qubits require 10-25mK operating temperatures
- Kiutra (Germany) already commercially deploys ADR-based He-3-free cooling systems
